The Searchlight is a piece of wargear that is commonly found on many human vehicles belonging to the Imperium and the Forces of Chaos, and can even be found in use by Tyranid Genestealers that are hidden on Imperial worlds. Searchlights are a low-cost vehicle upgrade for use during night fighting scenarios where the light can be used to illuminate enemy combatants, both making them more susceptible to weapons fire and temporarily blinding them. While searchlights are useful for illuminating enemies, it also has the unfortunate side-effect of making the vehicle with the searchlight more vulnerable to return fire from the enemy. The searchlights used by the Imperium, and human vehicles in general, are usually mounted upon full-motion swivel mounts located on top of the vehicle, or on the nose or lower fuselage of an aircraft. The searchlights themselves come in a wide variety of shapes and sizes, from ornate gilded lights on an Ecclesiarchy vehicle to the more utilitarian ones used by the Adeptus Astartes. Searchlights used by the vehicles of the Forces of Chaos are usually the same as they were before being captured by the Archenemy, albeit now covered in unholy runes and dark symbols.
Searchlights are not only confined to vehicles, and can be found attached to many buildings, defensive walls, sentry towers, and anywhere else a light would be of use. Searchlights are often used for non-military purposes, such as lighting landing pads, Adeptus Arbites checkpoints and prisons, and to illuminate important buildings for nothing more than show. During nighttime air raids against military installations or cities, powerful searchlights are pointed skywards, in an effort to aid ground-based anti-aircraft fire. The Imperium also makes use of mobile searchlights, such as those mounted on tripods or weapons platforms like the Sabre Gun Platform.
- Warhammer 40,000: Wargear (4th Edition), pg. 36
- Codex: Astra Militarum (6th Edition)
- Codex: Adepta Sororitas (6th Edition)
- Codex: Space Marines (7th Edition)
- Codex: Genestealer Cults (7th Edition)